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Transformation of fatty acid hydroperoxides by alkali and characterization of products
Author(s) -
Gardner Harold W.,
Simpson Thomas D.,
Hamberg Mats
Publication year - 1993
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02536079
Subject(s) - chemistry , yield (engineering) , alkali metal , fatty acid , linoleic acid , epoxy , stereochemistry , organic chemistry , materials science , metallurgy
It has previously been determined that (13 S ,9 Z ,11 E )‐13‐hydroperoxy‐9,11‐octadecadienoic acid was mainly converted into (13 S ,9 Z ,11 E )‐13‐hydroxy‐9,11‐octadecadienoic acid by 5 N KHO with preservation of the stereochemistry of the reactant [Simpson, T.D., and Gardner, H.W. (1993) Lipids 28 , 325–330]. In addition, about 20–25% of the reactant was converted into several unknown by‐products. In the present work it was confirmed that the stereochemistry was conserved during the hydroperoxy‐diene to hydroxydiene transformation, but also, novel by‐products were identified. It was found that after only 40 min reaction (9 Z )‐13‐oxo‐ trans ‐11,12‐epoxy‐9‐octadecenoic acid accumulated to as much as 7% of the total. Later, (9 Z )‐13‐oxo‐ trans ‐11,12‐epoxy‐9‐octadecenoic acid began to disappear, and several other compounds continued to increase in yield. Two of these compounds, 2‐butyl‐3,5‐tetradecadienedioic acid and 2‐butyl‐4‐hydroxy‐5‐tetradecenedioic acid, were shown to originate from (9 Z )‐13‐oxo‐ trans ‐11,12‐epoxy‐9‐octadecenoic acid, and they accumulated up to 2–3% each after 4 to 6 h. Some other lesser products included 11‐hydroxy‐9,12‐heptadecadienoic acid, 3‐hydroxy‐4‐tridecenedioic acid, 13‐oxo‐9,11‐octadecadienoic acid and 12,13‐epoxy‐11‐hydroxy‐9‐octadecenoic acid. Except for the latter two, most or all of the compounds could have originated from Favorskii rearrangement of the early product, (9 Z )‐13‐oxo‐ trans ‐11,12‐epoxy‐9‐octadecenoic acid, through a cyclopropanone intermediate.